At present, the server is being developed in two directions, one is the direction of a normal server, the other is the direction of a high-end server utilizing a high-performance multi-processing architecture. The high-end server includes a Symmetrical Multi-Processing (SMP) server utilizing an SMP architecture and a Cache Coherence-Non Uniform Memory Access (CC-Numa) server utilizing a CC-Numa architecture.
In an SMP server, a plurality of Central Processing Units (CPUs) operate symmetrically without primary and secondary relationships or dependent relationships among them. Each CPU shares the same physical Random Access Memory (RAM), and it takes each CPU the same time period to access the RAM at any address. Methods for extending an SMP server include adding RAM, using faster CPUs, adding CPUs, expanding I/O capabilities, and employing more external devices, such as disk storages, etc. The characteristics of a CC-Numa server are similar to those of an SMP server except that each CPU takes different periods to access local RAM and remote RAM.
A blade server is a low cost server platform with High Availability High Density (HAHD) designed specially for specific applications and high-density computer environments. Each of the blades in the blade server is a system mainboard which may start its own operating system, such as Windows NT/2000, Linux, Solaris, etc., through a local hard disk, with each of the blades serving as an independent server. In such an operating mode, each of the mainboards operates its own system and provides services for a designated user group without relationships among users. These blades may also be combined into a server cluster using system software. In the server cluster mode, all of the mainboards may be interconnected to provide a high-speed network environment, and share the resources to provide their respective services for the same user group. The performance of such a system may be improved by inserting new blades into the cluster. Since each blade is hot swappable, the system may be replaced easily and maintenance time may be minimized. In a blade server, CPUs may be configured into a variety of subsystems. The blade servers on the same rack may share the same set of devices including a CD driver, a floppy driver, a keyboard, a display, and a mouse via a new type of intelligent KVM switch board, so that a plurality of servers can be accessed, thereby facilitating the upgrade and maintenance of the system as well as the access of files on the blade servers.
At present, both a normal blade server and a multi-processing blade server in the prior art can meet the requirement for a high-performance and cost-effective server. However, interfaces and wiring at the slots on the backboard of a normal blade server, which are used for the insertion and interconnection of normal blades, are of normal blade-specific designs. The interfaces and wiring of a normal blade and those of a multiple-processing blade are not compatible with each other, as a result, it is difficult to flexibly configure the system by selecting the respective blades for various levels of services, and thus it is difficult to meet the requirement for a cost-effective server.